Field of the Invention
The present invention relates to a secondary battery including a current interrupt mechanism.
Description of Related Art
Secondary batteries such as lithium-ion secondary batteries are used in stationary storage battery systems used for suppressing power variation of for example, power sources for driving electric vehicles (EVs) and hybrid electric vehicles (HEVs or PHEVs), photovoltaics, and wind power generation, or used for peak shift of system power that allows power to be stored during the nighttime and to be used during the daytime. A high capacity property and a high output property are required for use in EVs, HEVs, and PHEVs, and for stationary storage batters systems. Accordingly, the size of individual batteries has increased and many batteries are connected to each other in series or in parallel when used.
Batteries for such use are required to be significantly safer compared with secondary batteries for use in small portable equipment because materials having very high reactivity are used, particularly in the case where non-aqueous electrolyte secondary batteries are used. Accordingly, prismatic secondary batteries for the above use include a current interrupt mechanism that interrupts an electrical connection between an external terminal and an electrode body when the pressure inside a battery exterior body is increased as disclosed in, for example, Japanese Published Unexamined Patent Application No. 2008-66254 (Patent Document 1), Japanese Published Unexamined Patent Application No. 2008-66255 (Patent Document 2), Japanese Published Unexamined Patent Application No. 2010-212034 (Patent Document 3), Japanese Published Unexamined Patent Application No. 2013-175428 (Patent Document 4), Japanese Published Unexamined Patent Application No. 2013-157099 (Patent Document 5).